The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government.
Know the risks and potential benefits of clinical studies and talk to your health care provider before participating.
Read our disclaimer for details.

Investigating the effects of non-invasive transcranial alternating current stimulation (tACS) as a treatment for auditory hallucinations in patients with schizophrenia.

Condition or disease

Intervention/treatment

Phase

SchizophreniaSchizo Affective Disorder

Device: tACS (alpha)Device: Sham tACS (alpha)

Not Applicable

Detailed Description:

The investigator's primary objective is to provide further evidence for the effectiveness of transcranial alternating current stimulation (tACS) to treat auditory hallucinations and to collect preliminary data on whether maintenance stimulation sessions can prolong the duration of stimulation-induced clinical benefits. The investigators will be looking into effects of tACS to re-normalize pathological alpha oscillations in the dorso-lateral prefrontal cortex (dl-PFC) of patients with schizophrenia or schizo-affective disorder by comparing Auditory Hallucination Rating Scale (AHRS) scores immediately before the first stimulation session, immediately after the last stimulation session, and at the end of the 8 weeks of maintenance sessions. As a secondary objective, the investigators will assess the differential clinical effects of active sham and 10Hz tACS on electroencephalogram (EEG) measures of alpha oscillations. The investigators will also be using source localization techniques in EEG analysis, based on individual locations of the scalp electrodes and anatomical structures with the use of structural magnetic resonance imaging (sMRI).

Participants will initially be randomized to either sham or 10 Hz tACS for the 5 consecutive days of stimulation. Participants will then be re-randomized to either sham or 10 Hz tACS for the 8 weeks of maintenance stimulation.

20 participants: 10 Hz tACS with a peak-to-peak amplitude of 2mA for 20 minutes twice daily during 5 consecutive days of stimulation, then 40 minutes once weekly for 8 weeks of maintenance stimulation.

Device: tACS (alpha)

Neuroconn DC Stimulator

Sham Comparator: Sham tACS (alpha)

20 participants: Will include 10 seconds of ramp in to 1 minute of 10 Hz tACS with a ramp out of 10 seconds for a total of 80 seconds of stimulation twice daily during 5 consecutive days of stimulation, then once weekly for 8 weeks of maintenance stimulation.

The investigators will compare the AHRS scores from immediately before the first stimulation (baseline) and immediately after the last stimulation as the primary outcomes measure.

Secondary Outcome Measures :

Electroencephalogram (EEG) [ Time Frame: Change across time from baseline measurement to final maintenance stimulation ]

The investigators will compare alpha oscillation power from resting state EEG recordings on the first and last day of stimulation. The investigators will also collect EEG recordings data at the 1st, 3rd, and final maintenance stimulation visits.

The investigators will compare the BACS scores immediately before the first stimulation (baseline) and immediately after the last stimulation.

Other Outcome Measures:

Electroencephalogram (EEG) Auditory Task [ Time Frame: Change across time from baseline measurement to final maintenance stimulation ]

The investigators will compare alpha oscillation power from resting state EEG recordings on the first and last day of stimulation. The investigators will also collect EEG recordings data at the 1st, 3rd, and final maintenance stimulation visits.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information

Ages Eligible for Study:

18 Years to 70 Years (Adult, Older Adult)

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

DSM-IV diagnosis of schizophrenia, any subtype, or schizoaffective disorder with refractory hallucinations. Duration of illness >1 year

18 - 70 years old

Clinical stable for at least 12 weeks i.e. not requiring any hospitalization or a change in level of care

On current antipsychotic doses for at least 4 weeks

Experience at least 3 auditory hallucinations per week

Stable auditory hallucinations as demonstrated by having less than or equal to 20% change in AHRS scores across a 2 week interval during the screening period

Capacity to understand all relevant risks and potential benefits of the study and to provide written informed consent, OR has a legal guardian who can provide the informed consent on the patient's behalf with the patient providing written assent to participate

Exclusion Criteria:

DSM-IV diagnosis of alcohol or substance abuse (other than nicotine) within the last month or a DSM-IV diagnosis of alcohol or substance dependence (other than nicotine) within the last 6 months